Weighing a Pig Without a Scale

By thePigSite.com - Ever wondered how to weigh a pig without a scale? This article explains how you can obtain a good estimate of a pigs weight by measuring its girth and length and doing some simple math.

The most accurate way to measure the weight of a pig is to use a specialist pig weigh. However, these can be expensive and if you only have a few pigs to weigh and a high degree of accuracy is not necessarily needed, we explain how to obtain a good estimate of a pigs weight using only a measuring tape and a calculator.

IMPERIAL - Weight of your pig in POUNDS

Obtain a fabric measuring tape or a piece of string to use as a measure. If using string mark the dimensions on the string and then measure the dimensions using a steel tape measure.

Place the tape/string under the pig just behind the front legs and measure the circumference of the pigs girth in inches. This measurement is known as the Heart Girth (see graphic)

Then measure the Length of the pig along its back from the base of its ears to the base of its tail, again in inches. (see graphic)

To calculate the pigs weight, first square the Heart Girth to get the Girth Result.

Now Multiply the Girth Result by the Length and DIVIDE by 400.

You now have the weight of your pig in Pounds.

Example:

Porky Pig has a Heart Girth of 50 inches and a Length of 40 inches.

Squaring the Heart Girth (50 x 50) = 2500 = Girth Result

Multiply the Girth Result (2500) by the Length (40) and divide by 400 = 250 Pounds.

METRIC VERSION - Weight of your pig in KILOGRAMMES

Use the same procedure as above taking your measurement in Meters.Then use the following formula.

Square the Heart Girth to get the Girth Result.

Now Multiply the Girth Result by the Length and MULTIPLY by 69.3

You now have the weight of your pig in Kg.

Example:

Porky Pig has a Heart Girth of 1.27 meters and a Length of 1.02 meters.

Squaring the Heart Girth (1.27 x 1.27) = 1.6129 = Girth Result

Multiply the Girth Result (1.6129) by the Length (1.02) and MULTIPLY by 69.3 = 114 Kg.

This procedure is reported to be accurate to within 3%.

CONVERSIONS

Alternatively use either procedure and convert the result to your chosen units.

To convert KILOGRAMMES to POUNDS multiply by 2.2
To convert POUNDS to KILOGRAMMES multiply by 0.455

LIVEWEIGHT vs DEADWEIGHT

The above formula gives you the liveweight of your pig. The conversion from liveweight to deadweight can vary somewhat, however using a ratio of 72% will give a good approximation. Thus in our example Pork Pig would have a carcass weight of around 180 pounds (250 x 0.72) or 82 Kg.